Page 181 - Ultrasonography in Prehospital and Emergency Medicine - Rein Ketelaars

Prehospital echocardiography during resuscitation impacts treatment in a physician-staffed HEMS 179
quality of ALS is vulnerable to the influence of previously identified unfavorable factors, such as emotional and physical stress of the caregivers, time, and environmental factors. In our operation with its heterogeneous case-mix and within a limited amount of time, essen- tial assessments and actions take precedence over ultrasound. Furthermore, we do not use ultrasound by default (yet) in every patient, let alone in every cardiac arrest case. Therefore, the ultrasound machine is not always brought to the incident site initially. Still, when it is present on-scene, it is not always used. A common scenario is that shortly after arrival on- scene either ROSC occurs or the ground ambulance team has already decided to terminate the resuscitation. Thus, there has not been any opportunity for echocardiography during CPR. Also, we might have omitted to use ultrasound because the cause of cardiac arrest was obvious or further treatment was deemed futile (e.g., a major injury with extensive blood loss).
A major limitation is the high number of missing CRFs. We speculate that some of the reasons might be nonadherence to the protocol, a lack of time due to subsequent missions, or plain forgetfulness. Another could be the dismissal of the entire procedure due to poor image quality, or the impression the scan contributed nothing to patient management. So, this might have introduced bias and possibly have led to over or underestimation of overall image quality and impacted decisions.
Unfortunately, in our operation, it is not possible to bring an independent observer on- scene. Therefore, ultrasound images could not be independently reviewed. Also, the impact of ultrasound on patient management was self-reported by the physicians after return to base. This could not be reported more objectively and might introduce bias. For instance, the effort physicians are making to perform echocardiography might make them more inclined to find utility. Or, the delay before the form is filled and other interventions performed in the meantime, might make the physician underestimate any added value when finally filling out the CRF.
The most frequent impacts on management were termination or continuation of resusci- tation and increasing the infusion of iv fluids. Although it sometimes appears the obvious choice to terminate resuscitative efforts, this decision is preferably supported by the entire team and is complex and multifactorial.13 The knowledge that sonographic cardiac standstill, in stark contrast to coordinated cardiac activity, predicts very poor (if any) survival improves the process of making a decision.7,8,14 We speculate this explains the number of times ultra- sound supported termination of treatment, although not every observed cardiac standstill justifies this immediately. Additionally, displaying the cardiac activity (or the lack thereof) can be of great value while explaining the prognosis and its implications to relatives and caregivers.
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